201
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Mares R, Bateman A, English S, Clutton-Brock T, Young A. Timing of predispersal prospecting is influenced by environmental, social and state-dependent factors in meerkats. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2013.11.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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202
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Seasonal evaluations of urinary androgen metabolites and semen quality in domestic long-tailed chinchilla (Chinchilla lanigera) under natural photoperiod. Anim Reprod Sci 2014; 145:99-104. [DOI: 10.1016/j.anireprosci.2014.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/21/2013] [Accepted: 01/08/2014] [Indexed: 11/23/2022]
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203
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Ogutu JO, Piepho HP, Dublin HT. Reproductive seasonality in African ungulates in relation to rainfall. WILDLIFE RESEARCH 2014. [DOI: 10.1071/wr13211] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Reproductive seasonality in ungulates has important fitness consequences but its relationship to resource seasonality is not yet fully understood, especially for ungulates inhabiting equatorial environments.
Aims
We test hypotheses concerning synchronisation of conception or parturition peaks among African ungulates with seasonal peaks in forage quality and quantity, indexed by rainfall.
Methods
We relate monthly apparent fecundity and juvenile recruitment rates to monthly rainfall for six ungulate species inhabiting the Masai Mara National Reserve (Mara) of Kenya, using cross-correlation analysis and distributed lag non-linear models. We compare the phenology and synchrony of breeding among the Mara ungulates with those for other parts of equatorial East Africa, with bimodal rainfall and less seasonal forage variation, and for subtropical southern Africa, with unimodal rainfall distribution and greater seasonal forage variation.
Key results
Births were more synchronised for topi, warthog and zebra than for hartebeest, impala and giraffe in the Mara, and for impala and hartebeest in southern than in eastern Africa. This pattern is likely to reflect regional differences in climate and plant phenology, hider–follower dichotomy and grazing versus browsing. All six species except the browsing giraffe apparently time the conception to occur in one wet season and births to occur just before the onset or during the next wet season, so as to maximise high-quality forage intake during conception and parturition. Fecundity and recruitment rates among the African ungulates peak at intermediate levels of rainfall and are reduced at low or excessive levels of rainfall. Fecundity rate is most strongly positively correlated with rainfall pre-conception, during conception and during early gestation, followed by rainfall at about the time of parturition for all the grazers. For giraffe, fecundity rate is most strongly correlated with rainfall during the gestation period.
Conclusions
Rainfall seasonality strongly influences reproductive seasonality and juvenile recruitment among African ungulates. The interaction of the rainfall influence with life-history traits and other factors leads to wide interspecific and regional variation.
Implications
Global climate change, especially widening annual rainfall variation expected to result from global warming, could reduce the predictability of the timing of peak forage availability and quality based on meteorological cues, the length of time with adequate nutrition or both, and hence reduce reproductive success among tropical ungulates.
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204
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Otero J, L'Abée-Lund JH, Castro-Santos T, Leonardsson K, Storvik GO, Jonsson B, Dempson B, Russell IC, Jensen AJ, Baglinière JL, Dionne M, Armstrong JD, Romakkaniemi A, Letcher BH, Kocik JF, Erkinaro J, Poole R, Rogan G, Lundqvist H, Maclean JC, Jokikokko E, Arnekleiv JV, Kennedy RJ, Niemelä E, Caballero P, Music PA, Antonsson T, Gudjonsson S, Veselov AE, Lamberg A, Groom S, Taylor BH, Taberner M, Dillane M, Arnason F, Horton G, Hvidsten NA, Jonsson IR, Jonsson N, McKelvey S, Naesje TF, Skaala O, Smith GW, Saegrov H, Stenseth NC, Vøllestad LA. Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar). GLOBAL CHANGE BIOLOGY 2014; 20:61-75. [PMID: 23966281 DOI: 10.1111/gcb.12363] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 07/31/2013] [Indexed: 05/08/2023]
Abstract
Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo salar) emigrate from freshwater nursery areas during spring and early summer to feed and grow in the North Atlantic Ocean. The transition from the freshwater ('parr') stage to the migratory stage where they descend streams and enter salt water ('smolt') is characterized by morphological, physiological and behavioural changes where the timing of this parr-smolt transition is cued by photoperiod and water temperature. Environmental conditions in the freshwater habitat control the downstream migration and contribute to within- and among-river variation in migratory timing. Moreover, the timing of the freshwater emigration has likely evolved to meet environmental conditions in the ocean as these affect growth and survival of the post-smolts. Using generalized additive mixed-effects modelling, we analysed spatio-temporal variations in the dates of downstream smolt migration in 67 rivers throughout the North Atlantic during the last five decades and found that migrations were earlier in populations in the east than the west. After accounting for this spatial effect, the initiation of the downstream migration among rivers was positively associated with freshwater temperatures, up to about 10 °C and levelling off at higher values, and with sea-surface temperatures. Earlier migration occurred when river discharge levels were low but increasing. On average, the initiation of the smolt seaward migration has occurred 2.5 days earlier per decade throughout the basin of the North Atlantic. This shift in phenology matches changes in air, river, and ocean temperatures, suggesting that Atlantic salmon emigration is responding to the current global climate changes.
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Affiliation(s)
- Jaime Otero
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, Oslo, N-0316, Norway
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205
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Higgins JK, MacLean HJ, Buckley LB, Kingsolver JG. Geographic differences and microevolutionary changes in thermal sensitivity of butterfly larvae in response to climate. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12218] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jessica K. Higgins
- Department of Biology; University of North Carolina at Chapel Hill; Chapel Hill North Carolina 27599 USA
| | - Heidi J. MacLean
- Department of Biology; University of North Carolina at Chapel Hill; Chapel Hill North Carolina 27599 USA
| | - Lauren B. Buckley
- Department of Biology; University of North Carolina at Chapel Hill; Chapel Hill North Carolina 27599 USA
| | - Joel G. Kingsolver
- Department of Biology; University of North Carolina at Chapel Hill; Chapel Hill North Carolina 27599 USA
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206
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Williams CT, Barnes BM, Kenagy GJ, Buck CL. Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming. J Zool (1987) 2013. [DOI: 10.1111/jzo.12103] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- C. T. Williams
- Department of Biological Sciences; University of Alaska Anchorage; Anchorage AK USA
| | - B. M. Barnes
- Institute of Arctic Biology; University of Alaska Fairbanks; Fairbanks AK USA
| | - G. J. Kenagy
- Burke Museum and Department of Biology; University of Washington; Seattle WA USA
| | - C. L. Buck
- Department of Biological Sciences; University of Alaska Anchorage; Anchorage AK USA
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207
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Giacomini HC, Shuter BJ. Adaptive responses of energy storage and fish life histories to climatic gradients. J Theor Biol 2013; 339:100-11. [DOI: 10.1016/j.jtbi.2013.08.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 08/20/2013] [Accepted: 08/21/2013] [Indexed: 11/29/2022]
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208
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Aitken SN, Whitlock MC. Assisted Gene Flow to Facilitate Local Adaptation to Climate Change. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135747] [Citation(s) in RCA: 549] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sally N. Aitken
- Department of Forest and Conservation Sciences,
- Center for Forest Conservation Genetics, and
| | - Michael C. Whitlock
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada;
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209
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Trivedi AK, Rani S, Kumar V. Circadian adaptation to seasons: effects on activity behavior in subtropical House Sparrow,Passer domesticus. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2013.850888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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210
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Geographic variation in winter hardiness of a common agricultural pest, Leptinotarsa decemlineata, the Colorado potato beetle. Evol Ecol 2013. [DOI: 10.1007/s10682-013-9681-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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211
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Le Tallec T, Perret M, Théry M. Light pollution modifies the expression of daily rhythms and behavior patterns in a nocturnal primate. PLoS One 2013; 8:e79250. [PMID: 24236115 PMCID: PMC3827385 DOI: 10.1371/journal.pone.0079250] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 09/19/2013] [Indexed: 11/23/2022] Open
Abstract
Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14th night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes.
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Affiliation(s)
- Thomas Le Tallec
- Mécanismes Adaptatifs et Evolution, UMR 7179, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Martine Perret
- Mécanismes Adaptatifs et Evolution, UMR 7179, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Marc Théry
- Mécanismes Adaptatifs et Evolution, UMR 7179, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
- * E-mail:
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212
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Moraiti CA, Nakas CT, Papadopoulos NT. Diapause termination of Rhagoletis cerasi pupae is regulated by local adaptation and phenotypic plasticity: escape in time through bet-hedging strategies. J Evol Biol 2013; 27:43-54. [PMID: 24192292 DOI: 10.1111/jeb.12273] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 09/29/2013] [Accepted: 09/30/2013] [Indexed: 12/01/2022]
Abstract
Persistence and thriving of univoltine, herbivore insect species of the temperate zone rely on obligate diapause response that ensures winter survival and synchronization with host phenology. We used a stenophagous fruit fly (Rhagoletis cerasi) with obligate pupae diapause to determine genetic and environmental effects on diapause intensity of geographically isolated populations with habitat heterogeneity. Pupae from two Greek and one German populations with various gene flow rates were exposed at five constant chilling temperatures (0-12 °C) for different durations and then incubated at a high temperature until all adults have emerged. Pupae diapause intensity differs among Greek and German populations, suggesting an adaptive response to habitat heterogeneity (mostly differences in phenology patterns of local host cultivars). Moderately warm winter temperatures, such as 8 °C, promote diapause termination in all three populations. Insufficient chilling (short duration or warmer temperatures) regulates the expression of prolonged dormancy. Interestingly, extended chilling (longer than required for terminating diapause) 'return' pupae to another (facultative) cycle of dormancy enabling adults to emerge during the next appropriate 'window of time'; a strategy first time reported for univoltine insects. Consequently, diapause duration of R. cerasi is determined both by i) the adaptive response to local climatic conditions (annual dormancy) and ii) the plastic responses to interannual climatic variability resulting in two types of long life cycles within populations, prolonged and facultative dormancy as response to insufficient chilling and extended exposure to chilling, respectively. Long life cycles are expressed as a part of dormancy bet-hedging strategies of R. cerasi populations.
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Affiliation(s)
- C A Moraiti
- Department of Agriculture, Crop Production and Rural Environment, Laboratory of Entomology and Agricultural Zoology, University of Thessaly, N. Ionia (Volos), Greece
| | - C T Nakas
- Department of Agriculture, Crop Production and Rural Environment, Laboratory of Biometry, University of Thessaly, N. Ionia (Volos), Greece
| | - N T Papadopoulos
- Department of Agriculture, Crop Production and Rural Environment, Laboratory of Entomology and Agricultural Zoology, University of Thessaly, N. Ionia (Volos), Greece
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213
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Stoks R, Geerts AN, De Meester L. Evolutionary and plastic responses of freshwater invertebrates to climate change: realized patterns and future potential. Evol Appl 2013; 7:42-55. [PMID: 24454547 PMCID: PMC3894897 DOI: 10.1111/eva.12108] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 08/30/2013] [Indexed: 12/14/2022] Open
Abstract
We integrated the evidence for evolutionary and plastic trait changes in situ in response to climate change in freshwater invertebrates (aquatic insects and zooplankton). The synthesis on the trait changes in response to the expected reductions in hydroperiod and increases in salinity indicated little evidence for adaptive, plastic, and genetic trait changes and for local adaptation. With respect to responses to temperature, there are many studies on temporal trait changes in phenology and body size in the wild that are believed to be driven by temperature increases, but there is a general lack of rigorous demonstration whether these trait changes are genetically based, adaptive, and causally driven by climate change. Current proof for genetic trait changes under climate change in freshwater invertebrates stems from a limited set of common garden experiments replicated in time. Experimental thermal evolution experiments and common garden warming experiments associated with space-for-time substitutions along latitudinal gradients indicate that besides genetic changes, also phenotypic plasticity and evolution of plasticity are likely to contribute to the observed phenotypic changes under climate change in aquatic invertebrates. Apart from plastic and genetic thermal adjustments, also genetic photoperiod adjustments are widespread and may even dominate the observed phenological shifts.
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Affiliation(s)
- Robby Stoks
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
| | - Aurora N Geerts
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
| | - Luc De Meester
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven Leuven, Belgium
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214
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Rani S, Kumar V. Avian circannual systems: persistence and sex differences. Gen Comp Endocrinol 2013; 190:61-7. [PMID: 23631901 DOI: 10.1016/j.ygcen.2013.04.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/29/2013] [Accepted: 04/04/2013] [Indexed: 11/25/2022]
Abstract
Birds show adaptation in their physiology and behavior to daily and seasonal periodicities in the environment. A circannual clock system gates seasonal events in birds to happen at the most appropriate time of the year, since a mistiming will delay the event until the arrival of the favorable time next year. The circannual clocks, the self-sustained endogenous system, are expressed under aperiodic conditions with a period close to 12months. In stonechats, it has been shown that circannual rhythms in testicular and molt cycles persist for 12years; this suggests that circannual clocks are functional throughout the life of an individual. Circannual rhythms are synchronized with both the photoperiodic and non-photoperiodic cues, and a synchronized circannual rhythm provides information on annual timing of the physiological event. The integration of rigid circannual timekeeping with the cyclic environment ensures phenotypic plasticity that is required for successful survival of a species in its habitat. There can be however sex differences in the circannual rhythm characteristics and in the relationship between circannual rhythms and external environment. In few cases that have been investigated, females appear playing a larger role in defining the breeding season in the year in relation to the environment. There is no evidence for the involvement of circadian clock in the generation of circannual rhythms. Therefore, future researches need to focus on finding molecular gears that possibly form the neuroendocrine loop and are translated into a seasonal event. Here, we briefly review limited information that is available on circannual rhythms and their relationship with the external environment from a few bird species, inhabiting tropical and temperate environments.
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Affiliation(s)
- Sangeeta Rani
- Department of Zoology, DST-IRHPA Center for Excellence in Biological Rhythms Research, University of Lucknow, Lucknow 226 007, India.
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215
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Andrew NR, Hart RA, Jung MP, Hemmings Z, Terblanche JS. Can temperate insects take the heat? A case study of the physiological and behavioural responses in a common ant, Iridomyrmex purpureus (Formicidae), with potential climate change. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:870-880. [PMID: 23806604 DOI: 10.1016/j.jinsphys.2013.06.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 06/02/2023]
Abstract
Insects in temperate regions are predicted to be at low risk of climate change relative to tropical species. However, these assumptions have generally been poorly examined in all regions, and such forecasting fails to account for microclimatic variation and behavioural optimisation. Here, we test how a population of the dominant ant species, Iridomyrmex purpureus, from temperate Australia responds to thermal stress. We show that ants regularly forage for short periods (minutes) at soil temperatures well above their upper thermal limits (upper lethal temperature = 45.8 ± 1.3°C; CT(max) = 46.1°C) determined over slightly longer periods (hours) and do not show any signs of a classic thermal performance curve in voluntary locomotion across soil surface temperatures of 18.6-57°C (equating to a body temperature of 24.5-43.1°C). Although ants were present all year round, and dynamically altered several aspects of their thermal biology to cope with low temperatures and seasonal variation, temperature-dependence of running speed remained invariant and ants were unable to elevate high temperature tolerance using plastic responses. Measurements of microclimate temperature were higher than ant body temperatures during the hottest part of the day, but exhibited a stronger relationship with each other than air temperatures from the closest weather station. Generally close associations of ant activity and performance with microclimatic conditions, possibly to maximise foraging times, suggest I. purpureus displays highly opportunistic thermal responses and readily adjusts behaviour to cope with high trail temperatures. Increasing frequency or duration of high temperatures is therefore likely to result in an immediate reduction in foraging efficiency. In summary, these results suggest that (1) soil-dwelling temperate insect populations may be at higher risks of thermal stress with increased frequency or duration of high temperatures resulting from climate change than previously thought, however, behavioural cues may be able to compensate to some extent; and (2) indices of climate change-related thermal stress, warming tolerance and thermal safety margin, are strongly influenced by the scale of climate metrics employed.
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Affiliation(s)
- Nigel R Andrew
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia.
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216
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Altizer S, Ostfeld RS, Johnson PTJ, Kutz S, Harvell CD. Climate change and infectious diseases: from evidence to a predictive framework. Science 2013; 341:514-9. [PMID: 23908230 DOI: 10.1126/science.1239401] [Citation(s) in RCA: 643] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Scientists have long predicted large-scale responses of infectious diseases to climate change, giving rise to a polarizing debate, especially concerning human pathogens for which socioeconomic drivers and control measures can limit the detection of climate-mediated changes. Climate change has already increased the occurrence of diseases in some natural and agricultural systems, but in many cases, outcomes depend on the form of climate change and details of the host-pathogen system. In this review, we highlight research progress and gaps that have emerged during the past decade and develop a predictive framework that integrates knowledge from ecophysiology and community ecology with modeling approaches. Future work must continue to anticipate and monitor pathogen biodiversity and disease trends in natural ecosystems and identify opportunities to mitigate the impacts of climate-driven disease emergence.
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Affiliation(s)
- Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
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217
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Ware JV, Nelson OL, Robbins CT, Carter PA, Sarver BAJ, Jansen HT. Endocrine rhythms in the brown bear (Ursus arctos): Evidence supporting selection for decreased pineal gland size. Physiol Rep 2013; 1:e00048. [PMID: 24303132 PMCID: PMC3835004 DOI: 10.1002/phy2.48] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 12/21/2022] Open
Abstract
Many temperate zone animals adapt to seasonal changes by altering their physiology. This is mediated in large part by endocrine signals that encode day length and regulate energy balance and metabolism. The objectives of this study were to determine if the daily patterns of two important hormones, melatonin and cortisol, varied with day length in captive brown bears (Ursus arctos) under anesthetized and nonanesthetized conditions during the active (March-October) and hibernation periods. Melatonin concentrations varied with time of day and season in nonanesthetized female bears despite exceedingly low nocturnal concentrations (1-4 pg/mL) in the active season. In contrast, melatonin concentrations during hibernation were 7.5-fold greater than those during the summer in anesthetized male bears. Functional assessment of the pineal gland revealed a slight but significant reduction in melatonin following nocturnal light application during hibernation, but no response to beta-adrenergic stimulation was detected in either season. Examination of pineal size in two bear species bears combined with a phylogenetically corrected analysis of pineal glands in 47 other species revealed a strong relationship to brain size. However, pineal gland size of both bear species deviated significantly from the expected pattern. Robust daily plasma cortisol rhythms were observed during the active season but not during hibernation. Cortisol was potently suppressed following injection with a synthetic glucocorticoid. The results suggest that melatonin and cortisol both retain their ability to reflect seasonal changes in day length in brown bears. The exceptionally small pineal gland in bears may be the result of direct or indirect selection.
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Affiliation(s)
- Jasmine V Ware
- Departments of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University Pullman, Washington, 99164
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218
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Morellet N, Bonenfant C, Börger L, Ossi F, Cagnacci F, Heurich M, Kjellander P, Linnell JDC, Nicoloso S, Sustr P, Urbano F, Mysterud A. Seasonality, weather and climate affect home range size in roe deer across a wide latitudinal gradient within Europe. J Anim Ecol 2013; 82:1326-39. [DOI: 10.1111/1365-2656.12105] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 05/15/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Nicolas Morellet
- INRA; UR35 Comportement et Ecologie de la Faune Sauvage; Institut National de la Recherche Agronomique; B.P. 52627 31326 Castanet-Tolosan France
| | - Christophe Bonenfant
- Laboratoire de Biométrie et Biologie Évolutive; UMR CNRS 5558; Université Lyon 1; F-69622 Villeurbanne France
| | - Luca Börger
- Centre d’Études Biologiques de Chizé; CNRS (U.P.R. 1934) & INRA (USC 1339); F-79360 Villiers-en-Bois France
| | - Federico Ossi
- Laboratoire de Biométrie et Biologie Évolutive; UMR CNRS 5558; Université Lyon 1; F-69622 Villeurbanne France
- Biodiversity and Molecular Ecology Department; IASMA Research and Innovation Centre, Fondazione Edmund Mach; Via Mach 1 38010 San Michele all'Adige TN Italy
| | - Francesca Cagnacci
- Biodiversity and Molecular Ecology Department; IASMA Research and Innovation Centre, Fondazione Edmund Mach; Via Mach 1 38010 San Michele all'Adige TN Italy
| | - Marco Heurich
- Departement of Research and Documentation; Bavarian Forest National Park; Freyunger Str 2 94481 Grafenau Germany
| | - Petter Kjellander
- Grimsö Wildlife Research Station; Department of Ecology; Swedish University of Agricultural Science (SLU); SE-73091 Riddarhyttan Sweden
| | - John D. C. Linnell
- Norwegian Institute for Nature Research (NINA); PO Box 5685 Sluppen NO-7485 Trondheim Norway
| | - Sandro Nicoloso
- Research, Ecology and Environment Dimension (D.R.E.Am. Italia); Via Enrico Bindi 14 51100 Pistoia PT Italy
| | - Pavel Sustr
- Department of Biodiversity Research; Global Change Research Centre AS CR; Na Sádkách 7 České Budějovice Czech Republic
| | | | - Atle Mysterud
- Centre for Ecological and Evolutionary Synthesis; Department Biosciences; University of Oslo; P.O. Box 1066 Blindern NO-0316 Oslo Norway
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219
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Helm B, Ben-Shlomo R, Sheriff MJ, Hut RA, Foster R, Barnes BM, Dominoni D. Annual rhythms that underlie phenology: biological time-keeping meets environmental change. Proc Biol Sci 2013; 280:20130016. [PMID: 23825201 DOI: 10.1098/rspb.2013.0016] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Seasonal recurrence of biological processes (phenology) and its relationship to environmental change is recognized as being of key scientific and public concern, but its current study largely overlooks the extent to which phenology is based on biological time-keeping mechanisms. We highlight the relevance of physiological and neurobiological regulation for organisms' responsiveness to environmental conditions. Focusing on avian and mammalian examples, we describe circannual rhythmicity of reproduction, migration and hibernation, and address responses of animals to photic and thermal conditions. Climate change and urbanization are used as urgent examples of anthropogenic influences that put biological timing systems under pressure. We furthermore propose that consideration of Homo sapiens as principally a 'seasonal animal' can inspire new perspectives for understanding medical and psychological problems.
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Affiliation(s)
- Barbara Helm
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.
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220
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Steen DA, McClure CJ, Graham SP. Relative influence of weather and season on anuran calling activity. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2012-0266] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Drivers of anuran reproductive activity may include multiple and independent environmental variables. To determine the relative influence of season, temperature, and precipitation in initiating frog reproduction, we monitored a species-rich frog assemblage in south-central Alabama for 3 years and modeled calling activity of vocalizing males, who call to attract mates. We evaluated multiple hypotheses potentially explaining calling activity and we were able to identify significant influences of calling activity for all 11 anuran species considered in the analysis. Eight species were significantly influenced by month of survey and four of these were influenced by at least one additional environmental variable. In our study, precipitation was relatively unimportant in influencing calling activity, likely because breeding pools at the site are semipermanent and the species we sampled are not generally reliant on ephemeral wetlands. In general, our data suggest that different species within the same wetlands respond to different cues when initiating reproduction and calling activity is largely based on a combination of both environmental conditions and either seasonal changes or endogenous drivers.
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Affiliation(s)
- David A. Steen
- Joseph W. Jones Ecological Research Center, 3988 Jones Center Drive, Newton, GA 39870, USA
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | | | - Sean P. Graham
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
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221
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Dixit AS, Singh NS. Photoperiod and circadian rhythmicity in testicular response of the tree sparrow. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2012.692253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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222
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Understanding variation in behavioural responses to human-induced rapid environmental change: a conceptual overview. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.02.017] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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223
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Meuti ME, Denlinger DL. Evolutionary links between circadian clocks and photoperiodic diapause in insects. Integr Comp Biol 2013; 53:131-43. [PMID: 23615363 DOI: 10.1093/icb/ict023] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In this article, we explore links between circadian clocks and the clock involved in photoperiodic regulation of diapause in insects. Classical resonance (Nanda-Hamner) and night interruption (Bünsow) experiments suggest a circadian basis for the diapause response in nearly all insects that have been studied. Neuroanatomical studies reveal physical connections between circadian clock cells and centers controlling the photoperiodic diapause response, and both mutations and knockdown of clock genes with RNA interference (RNAi) point to a connection between the clock genes and photoperiodic induction of diapause. We discuss the challenges of determining whether the clock, as a functioning module, or individual clock genes acting pleiotropically are responsible for the photoperiodic regulation of diapause, and how a stable, central circadian clock could be linked to plastic photoperiodic responses without compromising the clock's essential functions. Although we still lack an understanding of the exact mechanisms whereby insects measure day/night length, continued classical and neuroanatomical approaches, as well as forward and reverse genetic experiments, are highly complementary and should enable us to decipher the diverse ways in which circadian clocks have been involved in the evolution of photoperiodic induction of diapause in insects. The components of circadian clocks vary among insect species, and diapause appears to have evolved independently numerous times, thus, we anticipate that not all photoperiodic clocks of insects will interact with circadian clocks in the same fashion.
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Affiliation(s)
- Megan E Meuti
- Department of Entomology, The Ohio State University, Columbus, OH 43210, USA.
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224
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O'Brien C, Unruh L, Zimmerman C, Bradshaw WE, Holzapfel CM, Cresko WA. Geography of the circadian gene clock and photoperiodic response in western North American populations of the three-spined stickleback Gasterosteus aculeatus. JOURNAL OF FISH BIOLOGY 2013; 82:827-839. [PMID: 23464546 PMCID: PMC4076159 DOI: 10.1111/jfb.12024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 11/14/2012] [Indexed: 06/01/2023]
Abstract
Controlled laboratory experiments were used to show that Oregon and Alaskan three-spined stickleback Gasterosteus aculeatus, collected from locations differing by 18° of latitude, exhibited no significant variation in length of the polyglutamine domain of the clock protein or in photoperiodic response within or between latitudes despite the fact that male and female G. aculeatus are photoperiodic at both latitudes. Hence, caution is urged when interpreting variation in the polyglutamine repeat (PolyQ) domain of the gene clock in the context of seasonal activities or in relationship to photoperiodism along geographical gradients.
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Affiliation(s)
- C O'Brien
- Institute of Ecology and Evolution, 5289 University of Oregon, Eugene, OR 97403-5289, USA
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225
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Dominoni D, Quetting M, Partecke J. Artificial light at night advances avian reproductive physiology. Proc Biol Sci 2013; 280:20123017. [PMID: 23407836 DOI: 10.1098/rspb.2012.3017] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Artificial light at night is a rapidly increasing phenomenon and it is presumed to have global implications. Light at night has been associated with health problems in humans as a consequence of altered biological rhythms. Effects on wild animals have been less investigated, but light at night has often been assumed to affect seasonal cycles of urban dwellers. Using light loggers attached to free-living European blackbirds (Turdus merula), we first measured light intensity at night which forest and city birds are subjected to in the wild. Then we used these measurements to test for the effect of light at night on timing of reproductive physiology. Captive city and forest blackbirds were exposed to either dark nights or very low light intensities at night (0.3 lux). Birds exposed to light at night developed their reproductive system up to one month earlier, and also moulted earlier, than birds kept under dark nights. Furthermore, city birds responded differently than forest individuals to the light at night treatment, suggesting that urbanization can alter the physiological phenotype of songbirds. Our results emphasize the impact of human-induced lighting on the ecology of millions of animals living in cities and call for an understanding of the fitness consequences of light pollution.
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Affiliation(s)
- Davide Dominoni
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell 78315, Germany.
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226
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Ogutu JO, Piepho HP, Dublin HT. Responses of phenology, synchrony and fecundity of breeding by African ungulates to interannual variation in rainfall. WILDLIFE RESEARCH 2013. [DOI: 10.1071/wr13117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
The timing and synchrony of births are important components of fitness among ungulates living in seasonal environments.
Aims
We investigated the effects of rainfall variation on interannual variation in the timing, synchrony and prolificity of births for six African ungulate species inhabiting an equatorial savanna with bimodal rainfall.
Methods
We analyse how seasonally and aseasonally breeding African savanna ungulates maintain reproductive success despite rainfall constraints, and adjust the phenology, synchrony and fecundity of their breeding to track interannual variation in rainfall. We use data on six ungulate species inhabiting the Masai Mara National Reserve (Mara) of Kenya to test five hypotheses concerning the influences of seasonality in resources, gestation length and the hider–follower strategy on the timing, synchrony and prolificity of calving.
Key results
Births were more synchronised for topi, warthog and zebra than for hartebeest, impala, and giraffe. Births occurred in most months, but tended to peak during the early rains when forage quality peaks for all species. The rainfall component exerting the strongest influence on timing of births varied with species. Gestation length, the hider–follower dichotomy, and hence predation, had apparently weak influences on birth synchrony. In drought years with nutritionally deficient forage, births were delayed, less synchronised and fewer. This portrayed protracted calving seasons, suppression of early conceptions, and delayed onset of births, calf losses, reproductive pauses or failures. However, in rainy years with sufficient forage, births peaked early, or were not delayed, and the synchronicity of calving increased for all species. This suggested early breeding by primiparous females; or higher fertility early in the mating period. The prolificity of calving increased with rainfall for topi and warthog but decreased for the remaining species.
Conclusions
Marked interannual variability in rainfall, plant phenology and forage sufficiency in tropical savannas impose strong constraints on ungulates, favouring flexible timing of births over strictly seasonal reproduction characteristic of temperate latitudes with predictable seasonal resource cues.
Implications
Despite high flexibility in their timing of births, widening rainfall variability expected to result from global warming could lower reproductive success of tropical ungulates by lowering their fecundity and survival prospects of their calves if droughts became more frequent and severe.
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227
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Bradshaw WE, Emerson KJ, Catchen JM, Cresko WA, Holzapfel CM. Footprints in time: comparative quantitative trait loci mapping of the pitcher-plant mosquito, Wyeomyia smithii. Proc Biol Sci 2012; 279:4551-8. [PMID: 23015622 DOI: 10.1098/rspb.2012.1917] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Identifying regions of the genome contributing to phenotypic evolution often involves genetic mapping of quantitative traits. The focus then turns to identifying regions of 'major' effect, overlooking the observation that traits of ecological or evolutionary relevance usually involve many genes whose individual effects are small but whose cumulative effect is large. Herein, we use the power of fully interfertile natural populations of a single species of mosquito to develop three quantitative trait loci (QTL) maps: one between two post-glacially diverged populations and two between a more ancient and a post-glacial population. All demonstrate that photoperiodic response is genetically a highly complex trait. Furthermore, we show that marker regressions identify apparently 'non-significant' regions of the genome not identified by composite interval mapping, that the perception of the genetic basis of adaptive evolution is crucially dependent upon genetic background and that the genetic basis for adaptive evolution of photoperiodic response is highly variable within contemporary populations as well as between anciently diverged populations.
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Affiliation(s)
- William E Bradshaw
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA.
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228
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Cold resistance depends on acclimation and behavioral caste in a temperate ant. Naturwissenschaften 2012; 99:811-9. [PMID: 22955370 DOI: 10.1007/s00114-012-0963-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/16/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
Adjusting to low temperatures is important for animals living in cold environments. We studied the chill-coma recovery time in temperate ant workers (Temnothorax nylanderi) from colonies collected in autumn and spring in Germany. We experimentally acclimated these ant colonies to cold temperatures followed by warm temperatures. As expected, cold-acclimated workers recovered faster from freezing temperatures, but subsequent heat acclimation did not change the short recovery times observed after cold acclimation. Hence, either heat acclimation improves cold tolerance, possibly as a general response to stress, or at least it does not negate enhanced cold tolerance following cold acclimation. Colonies collected in spring showed similar cold tolerance levels to cold-acclimated colonies in the laboratory. Next, we compared the chill-coma recovery time of different worker castes and found that exterior workers recovered faster than interior workers. This difference may be related to their more frequent exposure to cold, higher activity level, or distinct physiology. Interior workers were also heavier and showed a higher gaster-to-head ratio and thorax ratio compared to exterior workers. An obvious difference between exterior and interior workers is activity level, but we found no link between activity and cold tolerance. This suggests that physiology rather than behavioral differences could cause the increased cold tolerance of exterior workers. Our study reveals the importance of acclimation for cold tolerance under natural and standardized conditions and demonstrates differences in cold tolerance and body dimensions in monomorphic behavioral castes of an ant.
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229
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Medger K, Chimimba CT, Bennett NC. Seasonal reproduction in the eastern rock elephant-shrew: influenced by rainfall and ambient temperature? J Zool (1987) 2012. [DOI: 10.1111/j.1469-7998.2012.00954.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- K. Medger
- Mammal Research Institute (MRI), Department of Zoology and Entomology; University of Pretoria; Hatfield; South Africa
| | | | - N. C. Bennett
- Mammal Research Institute (MRI), Department of Zoology and Entomology; University of Pretoria; Hatfield; South Africa
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230
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O'Brien CS, Bourdo R, Bradshaw WE, Holzapfel CM, Cresko WA. Conservation of the photoperiodic neuroendocrine axis among vertebrates: evidence from the teleost fish, Gasterosteus aculeatus. Gen Comp Endocrinol 2012; 178:19-27. [PMID: 22504272 PMCID: PMC3389224 DOI: 10.1016/j.ygcen.2012.03.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 01/11/2023]
Abstract
Photoperiod, or length of day, has a predictable annual cycle, making it an important cue for the timing of seasonal behavior and development in many organisms. Photoperiod is widely used among temperate and polar animals to regulate the timing of sexual maturation. The proper sensing and interpretation of photoperiod can be tightly tied to an organism's overall fitness. In photoperiodic mammals and birds the thyroid hormone pathway initiates sexual maturation, but the degree to which this pathway is conserved across other vertebrates is not well known. We use the threespine stickleback Gasterosteus aculeatus, as a representative teleost to quantify the photoperiodic response of key genes in the thyroid hormone pathway under controlled laboratory conditions. We find that the photoperiodic responses of the hormones are largely consistent amongst multiple populations, although differences suggest physiological adaptation to various climates. We conclude that the thyroid hormone pathway initiates sexual maturation in response to photoperiod in G. aculeatus, and our results show that more components of this pathway are conserved among mammals, birds, and teleost fish than was previously known. However, additional endocrinology, cell biology and molecular research will be required to define precisely which aspects of the pathway are conserved across vertebrates.
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Affiliation(s)
- Conor S O'Brien
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA.
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231
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Lehmann P, Lyytinen A, Sinisalo T, Lindström L. Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata). JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1146-1158. [PMID: 22705255 DOI: 10.1016/j.jinsphys.2012.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/02/2012] [Accepted: 06/04/2012] [Indexed: 06/01/2023]
Abstract
Organisms undergoing latitudinal range expansion face a change in the photoperiod which can lead to a mismatch between the timing of seasonal changes in physiological and life history traits with seasonal environmental changes. This mismatch can lead to lowered survival, for example, due to unsynchronized diapause timing. Successful range expansion even in recent introductions requires that organisms which use the photoperiod for seasonal predictions should show interpopulational differences in photoperiodic responses at different latitudes, as the photoperiod is a function of latitude. We investigated among population differences in photoperiodic responses of life history and physiological traits linked to diapause in the invasive beetle Leptinotarsa decemlineata. Beetles from a northern marginal and a southern European population were reared under short day (12:12L:D) and long day (18:6L:D) photoperiods. Both populations reacted similarly to the short day photoperiod. Their abdominal total lipid content increased and water content decreased which suggests that the beetles prepared for diapause. This was also indicated by low mortality during diapause. In the long day photoperiod large interpopulational differences were found, the southern population ceased lipid accumulation after 5 days, while the northern population continued lipid accumulation as beetles in the short day photoperiod. This indicates that the northern population has a longer critical photoperiod than the southern one. Abdominal total lipid stores in 10 day old beetles were shown to be predominantly composed of neutral lipids (85%), most likely representing storage triacylglycerols. Fatty acid profiles of both the neutral lipids and the phospholipids showed large shifts during the first 10 day of adult life, predominantly in the fractions of 18:0, 18:1ω9, 18:2ω6 and 18:3ω3. Although the degree of unsaturation increased with age, it was not higher in diapausing than non-diapausing beetles. This indicates that this species does not increase diapause related cold tolerance via homeoviscous adaptation, and might have developed other means to cope with suboptimal temperatures, such as behavioral adaptations.
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Affiliation(s)
- Philipp Lehmann
- Centre of Excellence in Biological Interactions Research, University of Jyväskylä, Finland.
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232
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Stevenson TJ, Hahn TP, MacDougall-Shackleton SA, Ball GF. Gonadotropin-releasing hormone plasticity: a comparative perspective. Front Neuroendocrinol 2012; 33:287-300. [PMID: 23041619 PMCID: PMC3484179 DOI: 10.1016/j.yfrne.2012.09.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 11/16/2022]
Abstract
Gonadotropin-releasing hormone 1 (GnRH1) is a key regulator of the reproductive neuroendocrine system in vertebrates. Recent developments have suggested that GnRH1 neurons exhibit far greater plasticity at the cellular and molecular levels than previously thought. Furthermore, there is growing evidence that sub-populations of GnRH1 neurons in the preoptic area are highly responsive to specific environmental and hormonal conditions. In this paper we discuss findings that reveal large variation in GnRH1 mRNA and protein expression that are regulated by social cues, photoperiod, and hormonal feedback. We draw upon studies using histochemistry and immediate early genes (e.g., c-FOS/ZENK) to illustrate that specific groups of GnRH1 neurons are topographically organized. Based on data from diverse vertebrate species, we suggest that GnRH1 expression within individuals is temporally dynamic and this plasticity may be evolutionarily conserved. We suggest that the plasticity observed in other neuropeptide systems (i.e. kisspeptin) may have evolved in a similar manner.
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Affiliation(s)
- T J Stevenson
- Institute for Mind and Biology, University of Chicago, Chicago, IL 60637, USA.
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233
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English AK, Chauvenet ALM, Safi K, Pettorelli N. Reassessing the determinants of breeding synchrony in ungulates. PLoS One 2012; 7:e41444. [PMID: 22911793 PMCID: PMC3401108 DOI: 10.1371/journal.pone.0041444] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 06/21/2012] [Indexed: 11/18/2022] Open
Abstract
Predicting the consequences of climate change is a major challenge in ecology and wildlife management. While the impact of changes in climatic conditions on distribution ranges has been documented for many organisms, the consequences of changes in resource dynamics for species' overall performance have seldom been investigated. This study addresses this gap by identifying the factors shaping the reproductive synchrony of ungulates. In temporally-variable environments, reproductive phenology of individuals is a key determinant of fitness, with the timing of reproduction affecting their reproductive output and future performance. We used a satellite-based index of resource availability to explore how the level of seasonality and inter-annual variability in resource dynamics affect birth season length of ungulate populations. Contrary to what was previously thought, we found that both the degree of seasonal fluctuation in resource dynamics and inter-annual changes in resource availability influence the degree of birth synchrony within wild ungulate populations. Our results highlight how conclusions from previous interspecific analyses, which did not consider the existence of shared life-history among species, should be treated with caution. They also support the existence of a multi-faceted link between temporal variation in resource availability and breeding synchrony in terrestrial mammals, and increase our understanding of the mechanisms shaping reproductive synchrony in large herbivores, thus enhancing our ability to predict the potential impacts of climate change on biodiversity.
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Affiliation(s)
- Annie K. English
- Imperial College London, Division of Biology, Ascot, United Kingdom
- The Zoological Society of London, Institute of Zoology, London, United Kingdom
| | - Aliénor L. M. Chauvenet
- Imperial College London, Division of Biology, Ascot, United Kingdom
- The Zoological Society of London, Institute of Zoology, London, United Kingdom
| | - Kamran Safi
- Max Planck Institute for Ornithology, Radolfzell, Germany
| | - Nathalie Pettorelli
- The Zoological Society of London, Institute of Zoology, London, United Kingdom
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234
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Dixit AS, Singh NS. Seasonal Variation in Sensitivity of the Photoperiodic Response System in the Subtropical Tree Sparrow (Passer montanus). ACTA ACUST UNITED AC 2012; 317:488-98. [DOI: 10.1002/jez.1741] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/14/2012] [Accepted: 06/05/2012] [Indexed: 11/09/2022]
Affiliation(s)
- Anand S. Dixit
- Department of Zoology; North-Eastern Hill University; Shillong; Meghalaya; India
| | - Namram S. Singh
- Department of Zoology; North-Eastern Hill University; Shillong; Meghalaya; India
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235
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Kovach RP, Gharrett AJ, Tallmon DA. Genetic change for earlier migration timing in a pink salmon population. Proc Biol Sci 2012; 279:3870-8. [PMID: 22787027 DOI: 10.1098/rspb.2012.1158] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To predict how climate change will influence populations, it is necessary to understand the mechanisms, particularly microevolution and phenotypic plasticity, that allow populations to persist in novel environmental conditions. Although evidence for climate-induced phenotypic change in populations is widespread, evidence documenting that these phenotypic changes are due to microevolution is exceedingly rare. In this study, we use 32 years of genetic data (17 complete generations) to determine whether there has been a genetic change towards earlier migration timing in a population of pink salmon that shows phenotypic change; average migration time occurs nearly two weeks earlier than it did 40 years ago. Experimental genetic data support the hypothesis that there has been directional selection for earlier migration timing, resulting in a substantial decrease in the late-migrating phenotype (from more than 30% to less than 10% of the total abundance). From 1983 to 2011, there was a significant decrease--over threefold--in the frequency of a genetic marker for late-migration timing, but there were minimal changes in allele frequencies at other neutral loci. These results demonstrate that there has been rapid microevolution for earlier migration timing in this population. Circadian rhythm genes, however, did not show any evidence for selective changes from 1993 to 2009.
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Affiliation(s)
- Ryan P Kovach
- Biology and Wildlife Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
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236
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Zerbe P, Clauss M, Codron D, Bingaman Lackey L, Rensch E, Streich JW, Hatt JM, Müller DWH. Reproductive seasonality in captive wild ruminants: implications for biogeographical adaptation, photoperiodic control, and life history. Biol Rev Camb Philos Soc 2012; 87:965-90. [DOI: 10.1111/j.1469-185x.2012.00238.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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237
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Currylow AF, MacGowan BJ, Williams RN. Short-term forest management effects on a long-lived ectotherm. PLoS One 2012; 7:e40473. [PMID: 22792344 PMCID: PMC3391286 DOI: 10.1371/journal.pone.0040473] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022] Open
Abstract
Timber harvesting has been shown to have both positive and negative effects on forest dwelling species. We examined the immediate effects of timber harvests (clearcuts and group selection openings) on ectotherm behavior, using the eastern box turtle as a model. We monitored the movement and thermal ecology of 50 adult box turtles using radiotelemetry from May-October for two years prior to, and two years following scheduled timber harvests in the Central Hardwoods Region of the U.S. Annual home ranges (7.45 ha, 100% MCP) did not differ in any year or in response to timber harvests, but were 33% larger than previous estimates (range 0.47-187.67 ha). Distance of daily movements decreased post-harvest (from 22 m±1.2 m to 15 m±0.9 m) whereas thermal optima increased (from 23±1°C to 25±1°C). Microclimatic conditions varied by habitat type, but monthly average temperatures were warmer in harvested areas by as much as 13°C. Animals that used harvest openings were exposed to extreme monthly average temperatures (∼40°C). As a result, the animals made shorter and more frequent movements in and out of the harvest areas while maintaining 9% higher body temperatures. This experimental design coupled with radiotelemetry and behavioral observation of a wild ectotherm population prior to and in response to anthropogenic habitat alteration is the first of its kind. Our results indicate that even in a relatively contiguous forested landscape with small-scale timber harvests, there are local effects on the thermal ecology of ectotherms. Ultimately, the results of this research can benefit the conservation and management of temperature-dependent species by informing effects of timber management across landscapes amid changing climates.
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Affiliation(s)
- Andrea F Currylow
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, United States of America.
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238
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Clark ME, Reed WL. Seasonal interactions between photoperiod and maternal effects determine offspring phenotype in Franklin's gull. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.02010.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Mark E. Clark
- Department of Biological Sciences; North Dakota State University; P.O. Box 6050; Dept. 2715; Fargo; North Dakota; 58108-6050; USA
| | - Wendy L. Reed
- Department of Biological Sciences; North Dakota State University; P.O. Box 6050; Dept. 2715; Fargo; North Dakota; 58108-6050; USA
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239
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Goymann W, Helm B, Jensen W, Schwabl I, Moore IT. A tropical bird can use the equatorial change in sunrise and sunset times to synchronize its circannual clock. Proc Biol Sci 2012; 279:3527-34. [PMID: 22648153 DOI: 10.1098/rspb.2012.0743] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
At higher latitudes, most organisms use the periodic changes in day length to time their annual life cycle. At the equator, changes in day length are minimal, and it is unknown which cues organisms use to synchronize their underlying circannual rhythms to environmental conditions. Here, we demonstrate that the African stonechat (Saxicola torquatus axillaris)-an equatorial songbird-can use subtle solar cues for the annual timing of postnuptial moult, a reliable marker of the circannual cycle. We compared four groups that were kept over more than 3 years: (i) a control group maintained under constant equatorial day length, (ii) a 12-month solar time group maintained under equatorial day length, but including a simulation of the annual periodic change in sunrise and sunset times (solar time), (iii) a 14-month solar time group similar to the previous group but with an extended solar time cycle and (iv) a group maintained under a European temperate photoperiod. Within all 3 years, 12-month solar time birds were significantly more synchronized than controls and 14-month solar time birds. Furthermore, the moult of 12-month solar time birds occurred during the same time of the year as that of free-living Kenyan conspecifics. Thus, our data indicate that stonechats may use the subtle periodic pattern of sunrise and sunset at the equator to synchronize their circannual clock.
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Affiliation(s)
- Wolfgang Goymann
- Max-Planck-Institut für Ornithologie, Abteilung für Verhaltensneurobiologie, Eberhard-Gwinner-Straße 6A, 82319 Seewiesen, Germany.
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240
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Vesala L, Salminen TS, Kankare M, Hoikkala A. Photoperiodic regulation of cold tolerance and expression levels of regucalcin gene in Drosophila montana. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:704-709. [PMID: 22360999 DOI: 10.1016/j.jinsphys.2012.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 05/31/2023]
Abstract
Temperature-induced plasticity of cold tolerance has been reported in many insect species, but cold tolerance can also be affected by changes in day (or night) length. In the present study we elucidate the direct and indirect effects of photoperiod on the cold tolerance of females of two Drosophila montana strains--one which possesses a robust photoperiodic diapause and another which does not. In the diapause-strain the time needed for recovery from chill coma showed a positive correlation with day length, but diapause itself played only a minor role in photoperiodic acclimation. The strain that was not able to enter to diapause as a response to day length also lacked photoperiodic cold acclimation ability indicating that this strain has deficiencies in its photoperiodic time measurement system. In the diapause-strain, the expression level of regucalcin gene was more than two times higher in diapausing than in non-diapausing females maintained in a single photoperiod, but day length per se did not cause significant changes in expression levels of this gene in either of the strains. In the non-diapausing strain this gene showed no expression changes in any comparison. Overall, the study shows that a decrease in day length can induce cold acclimation in D. montana, while changes in regucalcin expression are linked with photoperiodic diapause.
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Affiliation(s)
- L Vesala
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
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241
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Medger K, Chimimba CT, Bennett NC. Seasonal changes in reproductive development in male spiny mice (Acomys spinosissimus) from South Africa. Mamm Biol 2012. [DOI: 10.1016/j.mambio.2011.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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242
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243
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Crossin GT, Dawson A, Phillips RA, Trathan PN, Gorman KB, Adlard S, Williams TD. Seasonal patterns of prolactin and corticosterone secretion in an Antarctic seabird that moults during reproduction. Gen Comp Endocrinol 2012; 175:74-81. [PMID: 22020257 DOI: 10.1016/j.ygcen.2011.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/27/2011] [Accepted: 10/03/2011] [Indexed: 11/15/2022]
Abstract
In avian species that have evolved life-history strategies wherein molt and breeding overlap, there are potential conflicts between the regulatory roles of baseline prolactin and corticosterone in parental care (positive) and moult (negative). We describe seasonal patterns of hormonal secretion, moult, and parental behaviour in sibling species of giant petrels (Macronectes spp.) which begin moult during the incubation/early chick-rearing stage of reproduction. With the exception of male Southern giant petrels (Macronectes giganteus), prolactin secretion and moult in Northern (Macronectes halli) and female Southern giant petrels conformed to those observed in all other avian species, with the initiation of moult coincident with decreases from peak prolactin levels. However, male Southern giant petrels began moulting early in incubation when prolactin was increasing and had not yet peaked, which suggests a requirement of prolactin for incubation behaviour and a dissociation of prolactin from moult. Corticosterone showed little seasonal variation and no relationship with moult. When comparing prolactin, corticosterone, and moult in failed vs. active breeders, we found that failed breeding enabled a more rapid down-regulation of prolactin, thus facilitating a more rapid moult. We present specific examples of the behavioural ecology of giant petrels which we conclude help mediate any potential hormonal conflicts between parental care and moult.
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Affiliation(s)
- Glenn T Crossin
- Centre for Ecology and Hydrology, Natural Environment Research Council, Bush Estate, Penicuik, Midlothian EH26 0QB, United Kingdom.
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244
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Budki P, Rani S, Kumar V. Persistence of circannual rhythms under constant periodic and aperiodic light conditions: sex differences and relationship with the external environment. J Exp Biol 2012; 215:3774-85. [DOI: 10.1242/jeb.065581] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The timing and duration of gonadal phases in the year indicates that breeding cycles are regulated by endogenous mechanisms. The present study on tropical Spotted Munia (Lonchura punctulata) investigates whether such mechanisms are based on circannual rhythms, and whether circannual rhythms between sexes differ in their relationship with the light environment. Birds were subjected to 12 h light per day (12L:12D), alternate days of light and darkness (24L:24D, LL/DD) and continuous light (LL), with L= 22 lux and D = <1 lux, for 28 months (mo) at constant temperature (18±1°C). Groups kept on natural day lengths (NDL) served as controls. Measurement of body mass, gonads, and molts of the primary wing feathers and body plumage at regular intervals showed that birds underwent repeated cycles in gonads and molt, but not in the body mass. In NDL, gonadal phases in both sexes cycled with 12 mo periods. In other conditions, males cycled with similar periods of about 11 mo, but females cycled with relatively large period variations, about 10 to 13 mo. Gonadal recrudescence – regression phase was longer in males than in females and, in both sexes, in the second year as compared to the first year. The molt of wing primaries was more closely coupled to gonadal maturation in groups on NDL and 12L:12D than in groups on LL and LL/DD, but this relationship drifted apart in the second year. Body plumage molts were relatively more highly variable in both the frequency and pattern. It is suggested that annual breeding cycle in spotted munia is regulated by the self-sustained circannual rhythms, which probably interact with the annual photoperiodic cycle to synchronize breeding cycles to calendar year. Both sexes seem to have independent timing strategies, but females appear to share a greater role in defining the reproductive season in relation with the environment.
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245
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Helm B, Gwinner E, Koolhaas A, Battley P, Schwabl I, Dekinga A, Piersma T. Avian migration: Temporal multitasking and a case study of melatonin cycles in waders. PROGRESS IN BRAIN RESEARCH 2012; 199:457-479. [DOI: 10.1016/b978-0-444-59427-3.00026-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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246
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Śniegula S, Johansson F, Nilsson-Örtman V. Differentiation in developmental rate across geographic regions: a photoperiod driven latitude compensating mechanism? OIKOS 2011. [DOI: 10.1111/j.1600-0706.2011.20015.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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247
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Kutcherov DA, Kipyatkov VE. Sexual dimorphism in photoperiodic plasticity of body mass in the green dock leaf beetle Gastrophysa viridula (Coleoptera, Chrysomelidae). J EVOL BIOCHEM PHYS+ 2011. [DOI: 10.1134/s0022093011050070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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248
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Bradshaw WE, Emerson KJ, Holzapfel CM. Genetic correlations and the evolution of photoperiodic time measurement within a local population of the pitcher-plant mosquito, Wyeomyia smithii. Heredity (Edinb) 2011; 108:473-9. [PMID: 22072069 DOI: 10.1038/hdy.2011.108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The genetic relationship between the daily circadian clock and the seasonal photoperiodic timer remains a subject of intense controversy. In Wyeomyia smithii, the critical photoperiod (an overt expression of the photoperiodic timer) evolves independently of the rhythmic response to the Nanda-Hamner protocol (an overt expression of the daily circadian clock) over a wide geographical range in North America. Herein, we focus on these two processes within a single local population in which there is a negative genetic correlation between them. We show that antagonistic selection against this genetic correlation rapidly breaks it down and, in fact, reverses its sign, showing that the genetic correlation is due primarily to linkage and not to pleiotropy. This rapid reversal of the genetic correlation within a small, single population means that it is difficult to argue that circadian rhythmicity forms the necessary, causal basis for the adaptive divergence of photoperiodic time measurement within populations or for the evolution of photoperiodic time measurement among populations over a broad geographical gradient of seasonal selection.
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Affiliation(s)
- W E Bradshaw
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA.
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249
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Medger K, Chimimba CT, Bennett NC. Reproductive photoresponsiveness in male spiny mice from
S
outh
A
frica. J Zool (1987) 2011. [DOI: 10.1111/j.1469-7998.2011.00872.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K. Medger
- Department of Zoology and Entomology Mammal Research Institute (MRI) University of Pretoria Pretoria South Africa
| | - C. T. Chimimba
- Department of Zoology and Entomology Mammal Research Institute (MRI) University of Pretoria Pretoria South Africa
- Department of Zoology and Entomology DST‐NRF Centre of Excellence for Invasion Biology University of Pretoria Pretoria South Africa
| | - N. C. Bennett
- Department of Zoology and Entomology Mammal Research Institute (MRI) University of Pretoria Pretoria South Africa
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250
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Grey KB, Burrell BD. Seasonal variation of long-term potentiation at a central synapse in the medicinal leech. ACTA ACUST UNITED AC 2011; 214:2534-9. [PMID: 21753047 DOI: 10.1242/jeb.057224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Long-term potentiation (LTP) is a persistent increase in synaptic transmission that is thought to contribute to a variety of adaptive processes including learning and memory. Although learning is known to undergo circannual variations, it is not known whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic and postsynaptic stimulation. LTP was observed during the April-October period, but no LTP was observed during the November-March period. Application of forskolin, a technique often used to produce chemical LTP, failed to elicit potentiation during the November-March period. Implementing stimulation patterns that normally result in long term depression (LTD) also failed to elicit any change in synaptic strength during the November-March period. These experiments indicate that LTP and LTD can be influenced by circannual rhythms and also suggest a seasonal influence on learning and memory.
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Affiliation(s)
- Kathryn B Grey
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine at University of South Dakota, Vermillion, SD 57069, USA
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